You might want to log your own activities on top of your trainer's workouts.
You can log an activity either from your dashboard (click on the '+' sign, then on 'Activity') or from your calendar:
Let's say you went for a 30-min run this morning.
Click on the '+' for today on the calendar
Select 'Activity'. The Activity window will open on the right
Choose 'Running' in the dropdown menu
Enter '30 min' in the 'For how long?' field. Your burnt calories will update automatically. If you know the distance you made, you can log it at the top in the 'Distance' field
Drag the intensity indicator to tell how hard it was
Once you're done, click on the 'Save' button at the top right
A feedback window will automatically pop up. Use the indicator to express how you felt about that activity
Now you can see your run added to your calendar! The green color at the left shows how I felt about the running. The green checkmark says the activity has been done.
If you go back to your dashboard (the first icon on the left in the main menu), you will see your stats being automatically updated according to that last log.